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Saturation Estimation with Complex Electrical Conductivity for Hydrate-Bearing Clayey Sediments:An Experimental Study 被引量:1
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作者 XING Lanchang ZHANG Shuli +8 位作者 ZHANG Huanhuan WU Chenyutong WANG Bin LAO Liyun WEI Wei HAN Weifeng WEI Zhoutuo GE Xinmin DENG Shaogui 《Journal of Ocean University of China》 CAS CSCD 2024年第1期173-189,共17页
Clays have considerable influence on the electrical properties of hydrate-bearing sediments.It is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation(S... Clays have considerable influence on the electrical properties of hydrate-bearing sediments.It is desirable to understand the electrical properties of hydrate-bearing clayey sediments and to build hydrate saturation(S_(h))models for reservoir evaluation and monitoring.The electrical properties of tetrahydrofuran-hydrate-bearing sediments with montmorillonite are characterized by complex conductivity at frequencies from 0.01 Hz to 1 kHz.The effects of clay and Sh on the complex conductivity were analyzed.A decrease and increase in electrical conductance result from the clay-swelling-induced blockage and ion migration in the electrical double layer(EDL),respectively.The quadrature conductivity increases with the clay content up to 10%because of the increased surface site density of counterions in EDL.Both the in-phase conductivity and quadrature conductivity decrease consistently with increasing Sh from 0.50 to 0.90.Three sets of models for Sh evaluation were developed.The model based on the Simandoux equation outperforms Archie’s formula,with a root-mean-square error(E_(RMS))of 1.8%and 3.9%,respectively,highlighting the clay effects on the in-phase conductivity.The fre-quency effect correlations based on in-phase and quadrature conductivities exhibit inferior performance(E_(RMS)=11.6%and 13.2%,re-spectively)due to the challenge of choosing an appropriate pair of frequencies and intrinsic uncertainties from two measurements.The second-order Cole-Cole formula can be used to fit the complex-conductivity spectra.One pair of inverted Cole-Cole parameters,i.e.,characteristic time and chargeability,is employed to predict S_(h) with an E_(RMS) of 5.05%and 9.05%,respectively. 展开更多
关键词 gas hydrate complex electrical conductivity hydrate-bearing clayey sediment hydrate saturation Simandoux equation frequency dispersion Cole-Cole formula
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Hydro-mechanical-electrical simulations of synthetic faults in two orthogonal directions with shear-induced anisotropy
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作者 Kazuki Sawayama Takuya Ishibashi +1 位作者 Fei Jiang Takeshi Tsuji 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第11期4428-4439,共12页
Fluid flow in fractures controls subsurface heat and mass transport,which is essential for developing enhanced geothermal systems and radioactive waste disposal.Fracture permeability is controlled by fracture microstr... Fluid flow in fractures controls subsurface heat and mass transport,which is essential for developing enhanced geothermal systems and radioactive waste disposal.Fracture permeability is controlled by fracture microstructure(e.g.aperture,roughness,and tortuosity),but in situ values and their anisotropy have not yet been estimated.Recent advances in geophysical techniques allow the detection of changes in electrical conductivity due to changes in crustal stress and these techniques can be used to predict subsurface fluid flow.However,the paucity of data on fractured rocks hinders the quantitative interpretation of geophysical monitoring data in the field.Therefore,considering different shear displacements and chemical erosions,an investigation was conducted into the hydraulic-electric relationship as an elevated stress change in fractures.The simulation of fracture flows was achieved using the lattice Boltzmann method,while the electrical properties were calculated through the finite element method,based on synthetic faults incorporating elastic-plastic deformation.Numerical results show that the hydraulic and electrical properties depend on the rock's geometric properties(i.e.fracture length,roughness,and shear displacement).The permeability anisotropy in the direction parallel or perpendicular to the shear displacement is also notable in high stress conditions.Conversely,the permeability econductivity(i.e.,formation factor)relationship is unique under all conditions and follows a linear trend in logarithmic coordinates.However,both matrix porosity and fracture spacing alter this relationship.Both increase the slope of the linear trend,thereby changing the sensitivity of electrical observations to permeability changes. 展开更多
关键词 Fracture flow Permeability electrical conductivity Lattice Boltzmann method ANISOTROPY Chemical erosion Enhanced geothermal system
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Extrusion 3D printing of carbon nanotube-assembled carbon aerogel nanocomposites with high electrical conductivity
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作者 Lukai Wang Jing Men +4 位作者 Junzong Feng Yonggang Jiang Liangjun Li Yijie Hu Jian Feng 《Nano Materials Science》 EI CAS CSCD 2024年第3期312-319,共8页
Carbon nanotubes(CNTs)with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels.However,there remains a major challenge for achieving the on-demand shapi... Carbon nanotubes(CNTs)with high aspect ratio and excellent electrical conduction offer huge functional improvements for current carbon aerogels.However,there remains a major challenge for achieving the on-demand shaping of carbon aerogels with tailored micro-nano structural textures and geometric features.Herein,a facile extrusion 3D printing strategy has been proposed for fabricating CNT-assembled carbon(CNT/C)aerogel nanocomposites through the extrusion printing of pseudoplastic carbomer-based inks,in which the stable dispersion of CNT nanofibers has been achieved relying on the high viscosity of carbomer microgels.After extrusion printing,the chemical solidification through polymerizing RF sols enables 3D-printed aerogel nanocomposites to display high shape fidelity in macroscopic geometries.Benefiting from the micro-nano scale assembly of CNT nanofiber networks and carbon nanoparticle networks in composite phases,3D-printed CNT/C aerogels exhibit enhanced mechanical strength(fracture strength,0.79 MPa)and typical porous structure characteristics,including low density(0.220 g cm^(-3)),high surface area(298.4 m^(2)g^(-1)),and concentrated pore diameter distribution(~32.8nm).More importantly,CNT nanofibers provide an efficient electron transport pathway,imparting 3D-printed CNT/C aerogel composites with a high electrical conductivity of 1.49 S cm^(-1).Our work would offer feasible guidelines for the design and fabrication of shape-dominated functional materials by additive manufacturing. 展开更多
关键词 Carbon aerogel Extrusion 3D printing Carbon nanotube electrical conductivity RHEOLOGY
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Ti_(3)AlC_(2−y)N_(y) carbonitride MAX phase solid solutions with tunable mechanical,thermal,and electrical properties
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作者 Weiwei Zhang Shibo Li +3 位作者 Shukai Fan Xuejin Zhang Xiachen Fan Guoping Bei 《Journal of Advanced Ceramics》 SCIE EI CAS CSCD 2024年第9期1473-1481,共9页
Changing the N content in the Ti_(3)AlC_(2−y)N_(y) MAX phase solid solutions allows for the fine-tuning of their properties.However,systematic studies on the synthesis and properties of Ti_(3)AlC_(2−y)N_(y) solid solu... Changing the N content in the Ti_(3)AlC_(2−y)N_(y) MAX phase solid solutions allows for the fine-tuning of their properties.However,systematic studies on the synthesis and properties of Ti_(3)AlC_(2−y)N_(y) solid solution bulks have not been reported thus far.Here,previously reported Ti_(3)AlC_(2−y)N_(y) solid solution bulks(y=0.3,0.5,0.8,and 1.0)were synthesized via hot pressing of their powder counterparts under optimized conditions.The prepared Ti_(3)AlC_(2−y)N_(y) bulks are dense and have a fine microstructure with grain sizes of 6–8μm.The influence of the N content on the mechanical properties,electrical conductivities,and coefficients of thermal expansion(CTEs)of the prepared Ti_(3)AlC_(2−y)N_(y) bulk materials was clarified.The flexural strength and Vickers hardness values increased with increasing N content,suggesting that solid solution strengthening effectively improved the mechanical properties of Ti_(3)AlC_(2−y)N_(y).Ti_(3)AlCN(y=1)had the highest Vickers hardness and flexural strength among the studied samples,reaching 5.54 GPa and 550 MPa,respectively.However,the electrical conductivity and CTEs of the Ti_(3)AlC_(2−y)N_(y) solid solutions decreased with increasing N content,from 8.93×10^(−6) to 7.69×10^(−6) K^(−1) and from 1.33×10^(6) to 0.95×10^(6) S/m,respectively.This work demonstrated the tunable properties of Ti_(3)AlC_(2−y)N_(y) solid solutions with varying N contents and widened the MAX phase family for fundamental studies and applications. 展开更多
关键词 MAX solid solutions Ti_(3)AlC_(2−y)N_(y) microstructure mechanical properties electrical conductivity thermal expansion
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GLOBAL UNIQUE SOLUTIONS FOR THE INCOMPRESSIBLE MHD EQUATIONS WITH VARIABLE DENSITY AND ELECTRICAL CONDUCTIVITY
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作者 Xueli KE 《Acta Mathematica Scientia》 SCIE CSCD 2024年第5期1747-1765,共19页
We study the global unique solutions to the 2-D inhomogeneous incompressible MHD equations,with the initial data(u0,B0)being located in the critical Besov space■and the initial densityρ0 being close to a positive co... We study the global unique solutions to the 2-D inhomogeneous incompressible MHD equations,with the initial data(u0,B0)being located in the critical Besov space■and the initial densityρ0 being close to a positive constant.By using weighted global estimates,maximal regularity estimates in the Lorentz space for the Stokes system,and the Lagrangian approach,we show that the 2-D MHD equations have a unique global solution. 展开更多
关键词 inhomogeneous MHD equations electrical conductivity global unique solutions
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Fabrication of Graphene/Cu Composite by Chemical Vapor Deposition and Effects of Graphene Layers on Resultant Electrical Conductivity
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作者 Xinyue Liu Yaling Huang +2 位作者 Yuyao Li Jie Liu Quanfang Chen 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第1期16-25,共10页
Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the pro... Graphene(Gr)has unique properties including high electrical conductivity;Thus,graphene/copper(Gr/Cu)composites have attracted increasing attention to replace traditional Cu for electrical applications. However,the problem of how to control graphene to form desired Gr/Cu composite is not well solved. This paper aims at exploring the best parameters for preparing graphene with different layers on Cu foil by chemical vapor deposition(CVD)method and studying the effects of different layers graphene on Gr/Cu composite’s electrical conductivity. Graphene grown on single-sided and double-sided copper was prepared for Gr/Cu and Gr/Cu/Gr composites. The resultant electrical conductivity of Gr/Cu composites increased with decreasing graphene layers and increasing graphene volume fraction. The Gr/Cu/Gr composite with monolayer graphene owns volume fraction of less than 0.002%,producing the best electrical conductivity up to59.8 ×10^(6)S/m,equivalent to 104.5% IACS and 105.3% pure Cu foil. 展开更多
关键词 chemical vapor deposition(CVD) Gr/Cu Gr/Cu/Gr graphene layers graphene volume fraction electrical conductivity
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Mechanical and Electrical Properties of Some Sn-Zn Based Lead-Free Quinary Alloys
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作者 Shihab Uddin Md. Abdul Gafur +1 位作者 Suraya Sabrin Soshi Mohammad Obaidur Rahman 《Materials Sciences and Applications》 2024年第7期213-227,共15页
Although there are many lead-free soldering alloys on the market, none of them have ideal qualities. The researchers are combining binary alloys with a variety of additional materials to create the soldering alloys’ ... Although there are many lead-free soldering alloys on the market, none of them have ideal qualities. The researchers are combining binary alloys with a variety of additional materials to create the soldering alloys’ features. The eutectic Sn-9Zn alloy is among them. This paper investigated the mechanical and electrical properties of Sn-9Zn-x (Ag, Cu, Sb);{x = 0.2, 0.4, and 0.6} lead-free solder alloys. The mechanical properties such as elastic modulus, ultimate tensile strength (UTS), yield strength (YS), and ductility were examined at the strain rates in a range from 4.17 10−3 s−1 to 208.5 10−3 s−1 at room temperature. It is found that increasing the content of the alloying elements and strain rate increases the elastic modulus, ultimate tensile strength, and yield strength while the ductility decreases. The electrical conductivity of the alloys is found to be a little smaller than that of the Sn-9Zn eutectic alloy. 展开更多
关键词 Lead-Free Solder Strain Rate Ultimate Tensile Strength DUCTILITY electrical Conductivity
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Thermal and Electrical Properties of Liquid Metal Gallium During Phase Transition
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作者 Xizu Wang Durga Venkata Maheswar Repaka +3 位作者 Ady Suwardi Qiang Zhu Jing Wu Jianwei Xu 《Transactions of Tianjin University》 EI CAS 2023年第3期209-215,共7页
Liquid metal gallium has been widely used in numerous fields, from nuclear engineering, catalysts, and energy storage to electronics owing to its remarkable thermal and electrical properties along with low viscosity a... Liquid metal gallium has been widely used in numerous fields, from nuclear engineering, catalysts, and energy storage to electronics owing to its remarkable thermal and electrical properties along with low viscosity and nontoxicity. Compared with high-temperature liquid metals, room-temperature liquid metals, such as gallium(Ga), are emerging as promising alternatives for fabricating advanced energy storage devices, such as phase change materials, by harvesting the advantageous properties of their liquid state maintained without external energy input. However, the thermal and electrical properties of liquid metals at the phase transition are rather poorly studied, limiting their practical applications. In this study, we reported on the physical properties of the solid–liquid phase transition of Ga using a custom-designed, solid–liquid electrical and thermal measurement system. We observed that the electrical conductivity of Ga progressively decreases with an increase in temperature. However, the Seebeck coefficient of Ga increases from 0.2 to 2.1 μV/K, and thermal conductivity from 7.6 to 33 W/(K·m). These electrical and thermal properties of Ga at solid–liquid phase transition would be useful for practical applications. 展开更多
关键词 Liquid metal GALLIUM electrical conductivity Thermal conductivity Seebeck coefficients Phase transition
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Machine Learning Mapping of Soil Apparent Electrical Conductivity on a Research Farm in Mississippi
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作者 Reginald S. Fletcher 《Agricultural Sciences》 2023年第7期915-924,共10页
Open-source and free tools are readily available to the public to process data and assist producers in making management decisions related to agricultural landscapes. On-the-go soil sensors are being used as a proxy t... Open-source and free tools are readily available to the public to process data and assist producers in making management decisions related to agricultural landscapes. On-the-go soil sensors are being used as a proxy to develop digital soil maps because of the data they can collect and their ability to cover a large area quickly. Machine learning, a subcomponent of artificial intelligence, makes predictions from data. Intermixing open-source tools, on-the-go sensor technologies, and machine learning may improve Mississippi soil mapping and crop production. This study aimed to evaluate machine learning for mapping apparent soil electrical conductivity (EC<sub>a</sub>) collected with an on-the-go sensor system at two sites (i.e., MF2, MF9) on a research farm in Mississippi. Machine learning tools (support vector machine) incorporated in Smart-Map, an open-source application, were used to evaluate the sites and derive the apparent electrical conductivity maps. Autocorrelation of the shallow (EC<sub>as</sub>) and deep (EC<sub>ad</sub>) readings was statistically significant at both locations (Moran’s I, p 0.001);however, the spatial correlation was greater at MF2. According to the leave-one-out cross-validation results, the best models were developed for EC<sub>as</sub> versus EC<sub>ad</sub>. Spatial patterns were observed for the EC<sub>as</sub> and EC<sub>ad</sub> readings in both fields. The patterns observed for the EC<sub>ad</sub> readings were more distinct than the EC<sub>as</sub> measurements. The research results indicated that machine learning was valuable for deriving apparent electrical conductivity maps in two Mississippi fields. Location and depth played a role in the machine learner’s ability to develop maps. 展开更多
关键词 Spatial Variability Machine Learning electrical Conductivity MAPPING Data Mining
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Effect of Zr and Sc on mechanical properties and electrical conductivities of Al wires 被引量:9
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作者 钞润泽 管西花 +4 位作者 管仁国 铁镝 连超 王祥 张俭 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第10期3164-3169,共6页
In order to obtain the Al wires with good mechanical properties and high electrical conductivities, conductive wires of Al-0.16 Zr, Al-0.16 Sc, Al-0.12Sc-0.04Zr(mass fraction, %) and pure Al(99.996%) were produced... In order to obtain the Al wires with good mechanical properties and high electrical conductivities, conductive wires of Al-0.16 Zr, Al-0.16 Sc, Al-0.12Sc-0.04Zr(mass fraction, %) and pure Al(99.996%) were produced with the diameter of 9.5 mm by continuous rheo-extrusion technology, and the extruded materials were heat treated and analyzed. The results show that the separate additions of 0.16% Sc and 0.16% Zr to pure Al improve the ultimate tensile strength but reduce the electrical conductivity, and the similar trend is found in the Al-0.12Sc-0.04 Zr alloy. After the subsequent heat treatment, the wire with the optimum comprehensive properties is Al-0.12Sc-0.04 Zr alloy, of which the ultimate tensile strength and electrical conductivity reach 160 MPa and 64.03%(IACS), respectively. 展开更多
关键词 alloy composition Al wires mechanical properties electrical conductivity continuous rheo-extrusion
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Electrical and mechanical properties of Cu-Cr-Zr alloy aged under imposed direct continuous current 被引量:6
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作者 王志强 钟云波 +5 位作者 饶显君 汪超 王江 张增光 任维丽 任忠鸣 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第5期1106-1111,共6页
The Cu-Cr-Zr alloys were aged at different temperatures for different time with different current densities. The results show that both the electrical conductivity and hardness are greatly improved after being aged wi... The Cu-Cr-Zr alloys were aged at different temperatures for different time with different current densities. The results show that both the electrical conductivity and hardness are greatly improved after being aged with current at a proper temperature. The electrical conductivity increases approximately linearly with increasing current density while the hardness remains constant. The microstructure observation reveals that a much higher density of dislocations and nanosized Cr precipitates appear after the imposition of current, which contributes to the higher electrical conductivity and hardness. The mechanism is related with three factors: 1) Joule heating due to the current, 2) migration of mass electrons, 3) solute atoms, vacancies, and dislocations promoted by electron wind force. 展开更多
关键词 Cu-Cr-Zr alloy electrical conductivity HARDNESS current ageing PRECIPITATION
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Enhanced thermal and electrical properties of poly (D,L-lactide)/ multi-walled carbon nanotubes composites by in-situ polymerization 被引量:5
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作者 李清华 周勤华 +4 位作者 邓丹 俞巧珍 谷俐 龚科达 徐科航 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第5期1421-1427,共7页
Biodegradable poly (D,L-lactide) (PLA)/carboxyl-functionalized multi-walled carbon nanotubes (c-MWCNTs) composites were achieved via in-situ polymerization. These as-prepared composite materials were characteriz... Biodegradable poly (D,L-lactide) (PLA)/carboxyl-functionalized multi-walled carbon nanotubes (c-MWCNTs) composites were achieved via in-situ polymerization. These as-prepared composite materials were characterized with FT-IR, XRD, TG, DSC, SEM, and high insulation resistance meter. The results demonstrate that the multi-walled carbon nanotube was carboxyl functionalized, which improved the collection between c-MWCNTs and PLA, and further realized the graft copolymerization of c-MWCNTs and PLA. There is a higher glass transition temperature and a lower pyrolysis temperature of PLA/c-MWCNTs composites than pure PLA. The c-MWCNTs gave a better dispersion than unmodified MWCNTs in the PLA matrix, and an even coating of PLA on the surface of c-MWCNTs was obtained, which increased the interfacial interaction. High insulation resistance analysis showed that the addition of c-MWCNTs increased the electric conductivity, and c-MWCNTs performed against the large dielectric coefficient and electrostatic state of PLA. These results demonstrated that c-MWCNTs modified PLA composites were beneficial for potential application in the development of heat-resisting and conductivity plastic engineering. 展开更多
关键词 in-situ polymerization multi-walled carbon nanotubes POLYLACTIDE thermal properties electrical conductivity
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Continuous changes in electrical conductivity of sodium aluminate solution in seeded precipitation 被引量:3
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作者 刘桂华 李铮 +3 位作者 齐天贵 周秋生 彭志宏 李小斌 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第12期4160-4166,共7页
The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pai... The mechanism of seeded precipitation of sodium aluminate solution was studied by measuring the seeded-precipitation rate and electrical conductivity online, as well as calculating the activity and fraction of ion pair. The results show that the electrical conductivity of sodium aluminate slurry linearly decreases with increasing aluminum hydroxide addition. Moreover, both the electrical conductivity of slurry and the difference in electrical conductivity between sodium aluminate solution and slurry remarkably decline in the first 60 min before gradually increasing in the preliminary 10 h and finally reaching almost the same level after 10 h. In low Na2 O concentration solution the activities of Na OH and Na Al(OH)4 in seeded precipitation are high, which can enlarge the difference in conductivity between slurry and solution. Additionally, more ion pairs exist in solution in preliminary seeded precipitation, and the adsorption of Na+Al(OH)4- on seed surface is likely to break the equilibrium of ion pair formation and to decrease the difference in conductivity in preliminary seeded precipitation. 展开更多
关键词 sodium aluminate solution seeded precipitation electrical conductivity activity coefficient ion pair
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Electrical conductivity of NaF-AlF_3-CaF_2-Al_2O_3-ZrO_2 molten salts 被引量:3
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作者 包莫日根高娃 王兆文 +3 位作者 高炳亮 石忠宁 胡宪伟 于江玉 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第12期3788-3792,共5页
The electrical conductivity of NaF-AlF3-CaF2-Al2O3-ZrO2 system was studied by a tube-type cell with fixed cell constant. The results show that the electrical conductivity of NaF-AlF3-3%Al2O3-3%CaF2-ZrO2 molten salt sy... The electrical conductivity of NaF-AlF3-CaF2-Al2O3-ZrO2 system was studied by a tube-type cell with fixed cell constant. The results show that the electrical conductivity of NaF-AlF3-3%Al2O3-3%CaF2-ZrO2 molten salt system decreases with increase of ZrO2 content in an interval of 0-5%. The increase of 1%ZrO2 results in a corresponding electrical conductivity decrease of 0.02 S/cm, and the equivalent conductivity increases with the increase of molar ratio of NaF to AlF3. When the temperature increases by 1 °C, the electrical conductivity increases by 0.004 S/cm. At last, the regression equations of electrical conductivity relative to temperature and ZrO2 are obtained by quadratic regression analysis. 展开更多
关键词 ZRO2 molten salt electrolysis electrical conductivity NAF ALF3 Al-Zr alloy
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Microstructure and water-swelling mechanism of red-bed mudstone in the Xining region,Northeastern Tibetan Plateau 被引量:1
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作者 Huan Guan Yong Ren +5 位作者 Sixiang Ling Xiyong Wu Tao Yu Xian Li Sen Wang Chunwei Sun 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第7期2537-2551,共15页
This paper examines the effect of the microstructure and electrical conductivity(EC)on the swelling ratio and pressure in red-bed mudstone sampled from arid areas in the Xining region in the northeastern Tibetan Plate... This paper examines the effect of the microstructure and electrical conductivity(EC)on the swelling ratio and pressure in red-bed mudstone sampled from arid areas in the Xining region in the northeastern Tibetan Plateau.A series of laboratory tests,including swelling experiments,X-ray diffraction(XRD),and scanning electron microscope(SEM),was carried out for mechanical and microstructural analysis.The coupled influence of the EC and microstructural parameters on the expansion ratio and pressure was investigated,and the weight coefficients were discussed by the entropy weight method.The results revealed an increasing exponential trend in EC,and the maximum swelling speed occurred at an EC of approximately 10 μS/cm.In addition,a method for predicting the expansion potential is proposed based on the microstructure,and its reliability is verified by comparing with swelling experimental results.In addition,according to the image analysis results,the ranges of the change in the clay minerals content(CMC),the fractal dimension(FD),the average diameter(AD)of pores,and the plane porosity(PP)are 23.75%-53%,1.08-1.17,7.53-22.45 mm,and 0.62%-1.25%,respectively.Moreover,mudstone swelling is negatively correlated with the plane porosity,fractal dimension and average diameter and is linearly correlated with the clay mineral content.Furthermore,the weight values prove that the microstructural characteristics,including FD,AD,and PP,are the main factors influencing the expansion properties of red-bed mudstones in the Xining region.Based on the combination of macro and micro-analyses,a quantitative analysis of the swelling process of mudstones can provide a better reference for understanding the mechanism of expansion behavior. 展开更多
关键词 MUDSTONES MICROSTRUCTURE Swelling characteristics electrical conductivity(EC) Scanning electron microscope Water-swelling
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Mechanical properties,electrical conductivity and microstructure of CuCrZr alloys treated with thermal stretch process 被引量:3
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作者 张蓓 张治国 李卫 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第7期2285-2292,共8页
CuCrZr alloys were treated with the thermal stretch process at various temperatures from 100 to 300℃.The results reveal that the thermal stretch process is successfully developed to manufacture the precipitation hard... CuCrZr alloys were treated with the thermal stretch process at various temperatures from 100 to 300℃.The results reveal that the thermal stretch process is successfully developed to manufacture the precipitation hardening CuCrZr alloys with a good combination of microhardness and electrical conductivity.By increasing the tensile elongations at each temperature from 100 to 300℃,the microhardness increases whereas the electrical conductivity decreases slightly.Cr-containing precipitate phases with a Nishiyama-Wasserman orientation relationship to the copper matrix were observed by TEM.The achievement of high micro-hardness and acceptable electrical conductivity in the thermal stretch treated alloys is ascribed to the interactions of the heteroatom solution,dislocation increment,grain refinement and dispersive precipitation effect. 展开更多
关键词 CuCrZr alloys thermal stretch treatment MICROHARDNESS electrical conductivity
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Ambient electrical conductivity of carbon cathode materials for aluminum reduction cells 被引量:1
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作者 朱骏 薛济来 +2 位作者 张亚楠 李想 陈通 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第11期3753-3759,共7页
The ambient electrical conductivity (AEC) of carbon cathode materials was investigated in respect to their open porosity, crystal structure and graphite content using hydrostatic method, four-probe technique and X-ray... The ambient electrical conductivity (AEC) of carbon cathode materials was investigated in respect to their open porosity, crystal structure and graphite content using hydrostatic method, four-probe technique and X-ray diffraction (XRD), respectively. The AEC is proportional to the specific conductivity (σ0) and the exponential of (1?ε) (ε is porosity) by a quasi-uniform formula based on the percolation theory. Theσ0 can reflect the intrinsic conductivity of the carbon cathodes free of pores, and it depends on the mean crystallite size parallel to the layer (002). The exponentn is dependent on the materials nature of the cathode aggregates, while an averaged value, 4.65, can practically work well with 5 types of cathode materials. The calculation ofσ0 can be extended to the graphitic cathodes containing different aggregates using the simple rule of mixture. 展开更多
关键词 carbon cathode electrical conductivity POROSITY crystal structure aluminium reduction cell
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Electrical conductivity of MO(MO=FeO,NiO)-containing CaO-MgO-SiO_2-Al_2O_3 slag with low basicity 被引量:3
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作者 孙长余 郭兴敏 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第7期1648-1654,共7页
As a fundamental study on recovery of valuable metals from nonferrous metallurgical slags,electrical conductivity values of MO(MO=FeO,NiO)-containing CaO-MgO-SiO2-Al2O3 slag with a low basicity were measured at diff... As a fundamental study on recovery of valuable metals from nonferrous metallurgical slags,electrical conductivity values of MO(MO=FeO,NiO)-containing CaO-MgO-SiO2-Al2O3 slag with a low basicity were measured at different temperatures using AC impedance spectroscopy.The result shows that the electrical conductivity increased from 1.4 S/m to 14.4 S/m with the increase of the temperature from 1 573 to 1 773 K and the content of MO which is less than 12% under the constant mass ratio of (CaO+MgO) to (SiO2+Al2O3) of 0.47.Moreover,the increase magnitude of the electrical conductivity was also promoted with the increase of the content of MO.The electrical conductivity of FeO-containing slags was close to that of NiO-containing slags when the content was less than 8%;however,it was obviously larger than that of NiO-containing slags when the content was 12%.The activation energy of the electrical conductivity decreased with the increase of MO content. 展开更多
关键词 FEO NIO molten slag electrical conductivity AC impedance spectroscopy
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Effective thermal and electrical conductivity of graphite nanoplatelet composites 被引量:1
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作者 周晓锋 张小松 周建成 《Journal of Southeast University(English Edition)》 EI CAS 2013年第2期158-161,共4页
The relationship between the thermal/electrical conductivity enhancement in graphite nanoplatelets (GNPs) composites and the properties of filling graphite nanoplatelets is studied. The effective thermal and electri... The relationship between the thermal/electrical conductivity enhancement in graphite nanoplatelets (GNPs) composites and the properties of filling graphite nanoplatelets is studied. The effective thermal and electrical conductivity enhancements of GNP-oil nanofluids and GNP-polyimide composites are measured. By taking into account the particle shape, the volume fraction, the thermal conductivity of filling particles and the base fluids, the thermal and electrical conductivity enhancements of GNP nanofluids are theoretically predicted by the generalized effective medium theory. Both the nonlinear dependence of effective thermal conductivity on the GNP volume fraction in nanofhiids and the very low percolation threshold for GNP-polyimide composites are well predicted. The theoretical predications are found to be in reasonably good agreement with the experimental data. The generalized effective medium theory can be used for predicting the thermal and electrical properties of GNP composites and it is still available for most of the thermal/electrical modifications in two-phase composites. 展开更多
关键词 graphite nanoplatelet nanofluids THERMALCONDUCTIVITY electrical conductivity percolation threshold
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Application of face centred cubic TiB powder as conductive filler for electrically conductive adhesives 被引量:1
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作者 赵健闯 胡建东 +1 位作者 焦东宁 S.TOSTO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第6期1773-1778,共6页
Face centred cubic(FCC) TiB ceramic powder synthesized by Ti-boronizing method was used as conductive filler to make ceramic electrically conductive adhesives(ECAs) with the polymer matrix.Electrically conductive ... Face centred cubic(FCC) TiB ceramic powder synthesized by Ti-boronizing method was used as conductive filler to make ceramic electrically conductive adhesives(ECAs) with the polymer matrix.Electrically conductive properties of the ceramic ECAs were studied.The bulk electrical resistivity varied with the powder content of the FCC-TiB in ECAs.The FCC-TiB filled ECAs also showed the percolation behavior that usually occurred for the metal-filled ECAs,the percolation threshold was located at the content of 60%FCC-TiB.A minimum value of 0.1 Ω·cm was obtained at a content of 75%FCC-TiB.In order to check the reliability of mechanical property,tensile test was done to measure the shear strength,and the shear strength dropped with increasing the content of FCC-TiB powders.It is about 12.26 MPa at the content of 70%TiB powders.The Cu filled ECAs were also prepared for comparison.The properties of the oxidation resistance of the two ECAs were evaluated.The results show that the ceramic ECAs have excellent oxidation resistance and better stability compared with the Cu filled ECAs. 展开更多
关键词 ceramic powder face centred cubic TIB electrically conductive adhesives bulk resistivity OXIDATION shear strength
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